Inventor · disambiguated record
Rex E. Duhn
Also filed as: DUHN REX E
17 granted patents·2 pending applications·278 citations·filing 1989–2023
95Inventor score
Technology areasE21B
Top patents by PatentIndex Score
19 records- 0193US7322407B2Wellhead isolation tool and method of fracturing a wellDUHN OIL TOOL INC·Filed 2005·Granted Jan 29, 2008·36 cites·41 claims
- 0291US8272433B2Wellhead isolation tool and wellhead assembly incorporating the sameDUHN REX E·Filed 2010·Granted Sep 25, 2012·11 cites·12 claims
- 0387US11976542B1Frac distribution towerDUHN REX E·Filed 2023·Granted May 7, 2024·1 cites·22 claims
- 0486US7416020B2Wellhead isolation tool, wellhead assembly incorporating the same, and method of fracturing a wellDUHN OIL TOOL INC·Filed 2007·Granted Aug 26, 2008·18 cites·31 claims
- 0585US8333237B2Wellhead isolation tool and wellhead assembly incorporating the sameDUHN REX E·Filed 2012·Granted Dec 18, 2012·6 cites·17 claims
- 0680US6920925B2Wellhead isolation toolDUHN OIL TOOL INC·Filed 2003·Granted Jul 26, 2005·56 cites·88 claims
- 0777US7520322B2Wellhead isolation tool and method of fracturing a wellDUHN OIL TOOL INC·Filed 2007·Granted Apr 21, 2009·10 cites·27 claims
- 0875US7726393B2Wellhead isolation tool and wellhead assembly incorporating the sameDUHN OIL TOOL INC·Filed 2008·Granted Jun 1, 2010·9 cites·28 claims
- 0972US6199914B1Drilling quick connectorsDUHN OIL TOOL INC·Filed 1999·Granted Mar 13, 2001·48 cites·51 claims
- 1066USRE43773EDrilling quick connectorsDUHN REX E·Filed 2006·Granted Oct 30, 2012·7 cites·110 claims
- 1160US6543533B2Well tubing rotatorDUHN OIL TOOL INC·Filed 2001·Granted Apr 8, 2003·24 cites·42 claims
- 1249US7493944B2Wellhead isolation tool and method of fracturing a wellDUHN OIL TOOL INC·Filed 2004·Granted Feb 24, 2009·11 cites·55 claims
- 1346US8863829B2Wellhead isolation tool and wellhead assembly incorporating the sameSEABOARD INTERNAT INC·Filed 2012·Granted Oct 21, 2014·0 cites·14 claims
- 1440USRE43697EDrilling quick connectorsDUHN REX E·Filed 2002·Granted Oct 2, 2012·3 cites·62 claims
- 1534US2003205385A1Connections for wellhead equipmentFiled 2003·Application pending·0 cites
- 1633US5611398ATwo-piece drilling flangeDUHN IND·Filed 1995·Granted Mar 18, 1997·16 cites·16 claims
- 1733US5303774ARing seal packerDUHN OIL TOOL INC·Filed 1992·Granted Apr 19, 1994·14 cites·23 claims
- 1833US2002070545A1Drilling quick connectorsFiled 2002·Application pending·0 cites
- 1930US4974676AGround subsiding wellheadDUHN OIL TOOL INC·Filed 1989·Granted Dec 4, 1990·8 cites·19 claims
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Identity basis: PatentsView inventor disambiguation (2025Q4-odp release). How scoring works →